Most disease experts think that the rise of Covid mutants will make vaccines useless in less than a year.
The stark warning came from a survey of 77 epidemiologists from 28 countries carried out by The People's Vaccine Alliance.
Two thirds of experts thought that the current batch of jabs currently going into millions of arms in the UK will become redundant in 12 months or less.
This is because coronavirus would have mutated to the extent that new or modified vaccines would be needed to keep up.
Of those surveyed, almost a third gave an even smaller time frame of just nine months or less.
Fewer than one in eight said they believed that mutations would never render the current vaccines ineffective, according to the research published by Oxfam.
The overwhelming majority —88 per cent— said that persistent low vaccine coverage in many countries would make it more likely for vaccine resistant mutations to appear.
Devi Sridhar, Professor of Global Public Health at the University of Edinburgh, said: “The more the virus circulates, the more likely it is that mutations and variants will emerge, which could make our current vaccines ineffective.
"At the same time, poor countries are being left behind without vaccines and basic medical supplies like oxygen.
“As we've learned, viruses don't care about borders. We have to vaccinate as many people as possible, everywhere in the world, as quickly as possible. Why wait and watch instead of getting ahead of this?”
Gregg Gonsalves, Associate Professor of Epidemiology at Yale University, added: “With millions of people around the world infected with this virus, new mutations arise every day.
"Sometimes they find a niche that makes them more fit than their predecessors.
"These lucky variants could transmit more efficiently and potentially evade immune responses to previous strains.
"Unless we vaccinate the world, we leave the playing field open to more and more mutations, which could churn out variants that could evade our current vaccines and require booster shots to deal with them.
“We all have a self-interest in ensuring that everyone around the world, no matter where they live have access to COVID-19 vaccines. The virus doesn’t respect borders and new variants somewhere on the planet mean none of us are safe.”
The vaccine rollout in the UK, which has reached more than 30million adults, will focus on second doses in April after a hit to expected supplies.
Thousands of people under 50 are now being called for Covid vaccines as households of those with a weakened immune system are to be prioritised for jabs.
The recommendation from the Joint Committee on Vaccination and Immunisation (JCVI), accepted by the Government, means some under-50s due to have their first doses delayed until at least May will now be able to access jabs.
Adults under-50 will still receive a first dose by July 31, the Government maintains.
Meanwhile, Boris Johnson on Monday announced that 60million doses of a new Novavax vaccine will be manufactured in the UK.
